President Biden said he plans to nominate Jonathan Kanter, who has long opposed Big Tech companies as a lawyer, to lead the Justice Department’s antitrust division. It’s the latest sign of the administration’s willingness to crack down on the power and influence of Silicon Valley titans.

Kanter is known as an adversary of giant tech corporations including Google and Apple. He has represented large companies like Microsoft, as well as smaller tech companies like Google critic Yelp. He is a partner at the Kanter Law Group, which describes itself as “an antitrust advocacy boutique.”

“Throughout his career, Kanter has also been a leading advocate and expert in the effort to promote strong and meaningful antitrust enforcement and competition policy,” the White House said in a news release.

The nomination would fill a critical vacancy amid a broader administration effort to crack down on concentration in the economy, particularly in the tech sector. Biden this month signed a sweeping executive order targeting corporate consolidation, which directly challenges the path that Google, Facebook, Amazon and Apple took to dominance.

Last month, he named Lina Khan, a prominent critic of the tech giants, to lead the nation’s other top antitrust enforcer, the Federal Trade Commission. Earlier this year, he named Tim Wu, a Columbia Law professor who spoke out about large tech companies, to the National Economic Council.

The nomination signals the dramatic deterioration of the tech industry’s relationship with the Democratic Party. The Obama administration had a famously close relationship with Google and other tech companies and opted not to bring major antitrust action against the search giant. But the selection of Kanter, Khan and Wu signals that Biden, who ran as a moderate Democrat, intends to take a dramatically different posture in enforcing competition laws.

Already the DOJ has been working on implementing Biden’s recent order, and it is working on a plan to better work with other agencies to enforce it, according to a memo sent to agency staff members earlier this month. The DOJ and FTC also announced that they were launching a joint review of mergers to ensure they “reflect current economic realities” following the Biden executive order.

Kanter will face a confirmation hearing, where his past work for Big Tech companies’ rivals could come under greater scrutiny.

The Justice Department is pursuing a historic antitrust complaint against Google, which was brought under the Trump administration. The agency is under pressure to more closely scrutinize the business practices and deals of Silicon Valley companies.

Google declined to comment on Kanter’s nomination.

The White House declined to say whether Kanter would need to recuse himself from the DOJ Google case. An official said the White House remains confident in Kanter’s track record and expertise.

Kanter’s rise follows pressure on other prominent antitrust enforcers to recuse themselves given their work before taking office. Makan Delrahim, who served as the top antitrust cop in the Trump Justice Department, recused himself from the Google investigation after he advised the search giant during its 2007 acquisition of the digital ad firm Double Click.

More recently, Khan has faced petitions from Facebook and Amazon, calling on her to recuse herself from antitrust cases involving their companies, given her past criticism of them in her academic writing and work on the congressional probe into Silicon Valley’s power. During her confirmation hearing, Khan said she had “none of the financial conflicts or personal ties that are the basis of recusal under federal ethics laws.”

Netchoice, a tech trade group whose members include Google, Amazon and Facebook, raised similar concerns about Kanter’s professional history.

“Given that Kanter is famous for representing Microsoft and Yelp and attacking Google, Kanter will raise questions about his ability to impartially enforce the law against tech businesses, just like FTC Chair Khan,” Netchoice vice president and general counsel Carl Szabo said in a statement.

Yet there’s growing support for greater antitrust enforcement among politicians in both parties, and they might not be deterred by the large tech companies’ line of attack. Khan’s nomination drew bipartisan support, and she was confirmed to the FTC on a 69-to-28 vote. Twenty-one Republicans joined 46 Democrats and two independents in supporting Khan.

Sen. Mike Lee (R-Utah), the top Republican on the Judiciary Committee antitrust panel, said he was “encouraged” by Kanter’s track record on challenging tech giants.

“I look forward to learning more about his qualifications through the confirmation process,” he said in a statement.

Kanter is already a player in some of the most prominent antitrust battles. In the recent legal showdown between Fortnite maker Epic Games and Apple over competition on the App Store, Kanter represented one of Epic’s key corporate allies, a small start-up called Yoga Buddhi, which makes the app Down Dog, according to court records. Benjamin Simon, the app’s co-founder, testified that Apple’s anti-competitive practices hurt his business.

Kanter was largely a favorite for the position among liberal antitrust reformers. For months, prominent critics of the tech companies have been posting images of themselves holding coffee mugs with the text “Wu& Khan& Kanter.” to reflect their support of greater antitrust enforcement. Rep. Jamaal Bowman (D-N.Y.) in May tweeted a photo of himself carrying one of the mugs.

Kanter’s nomination received praise from Democrats eager to see greater antitrust enforcement. Sen. Elizabeth Warren (D-Mass.), who led the calls to break up Big Tech as a candidate in the 2020 presidential primary election, said his nomination is “tremendous news for workers and consumers.”

“He’s been a leader in the fight to check consolidated corporate power and strengthen competition in our markets,” Warren tweeted.

Sen. Amy Klobuchar (D-Minn.), the chair of the Senate Judiciary antitrust panel, said Kanter is “an excellent choice.” She promised to “push to secure additional resources to support this critical effort.”

Congress is debating a bevy of measures to increase the resources of the Justice Department and FTC to make it easier for federal enforcers to bring competition challenges against dominant tech companies. A bipartisan set of bills targeting the tech giants’ business practices last month advanced out of a House committee, but it’s unclear when they’ll see a vote on the House floor.

Reps. Jerrold Nadler (N.Y.) and David N. Cicilline (R.I.), Democratic co-sponsors of that legislation and House Judiciary Committee leaders, said Kanter is “absolutely the right person for this job at this moment.”

“We applaud President Biden for continuing to put hardworking Americans ahead of corporate monopolies, and we look forward to working with the Justice Department as we advance legislation to lower prescription drug prices, prohibit anticompetitive conduct and mergers online, and modernize the antitrust laws,” they said in a joint statement.

Gerrit De Vynck contributed to this report.